Targeted delivery of botulinum toxin for the treatment and prevention of trigeminal autonomic cephalgias, migraine and vascular conditions

ABSTRACT

Botulinum toxin, among other presynaptic neurotoxins is used for the treatment and prevention of migraine and other headaches associated with vascular disorders. Presynaptic neurotoxins are delivered focally, targeting the nerve endings of the trigeminal nerve, the occipital nerve and the intranasal terminals of the parasympathetic fibers originating in the Sphenopalatine ganglion. The administration preferably targets the extracranial nerve endings of the trigeminal nerve in the temporal area, the extracranial occipital nerve endings in the occipital area, and the intranasal terminals of the trigeminal nerve and parasympathetic fibers originating in the Sphenopalatine ganglion. The delivery is carried out by way of injection or topically.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/593,641, filed Feb. 1, 2005.

BACKGROUND OF THE INVENTION

Migraine is a primary headache disorder that may be characterized by unilateral throbbing pain which worsens with head movement. This can be associated with other symptoms including nausea, light and noise sensitivity, lacrimation, nasal congestion, and rhinorrhea. An array of factors can trigger migraine headache, such as internal changes (hormonal changes, stress, sleep deprivation) or external changes (weather changes, alcohol, flickering light).

In some cases, a migraine attack begins with a premonitory visual aura. These patients experience a visual disturbance in the form of a zigzag spectrum around a blind spot, which grows in size over a 20-30 min period. This visual effect is known as the “fortification spectrum.” The development of the fortification spectrum over time has been shown to correspond to a wave of depression in the activity of cortical neurons, which typically begins in the occipital lobe, and spreads anteriorly. The establishment of this correspondence has permitted the elaboration of a theory about the pathophysiological changes that may cause migraine and other headaches.

As neurons depress, they release nitric oxide (NO), which triggers the dilation of meningeal blood vessels. This vasodilation can result in a dull headache, which corresponds to the earliest phase of migraine.

The dilation of the meningeal blood vessels increases the activity of the nerve endings of the primary afferent neurons of the trigeminal nerve that are wrapped around them. As a result, the trigeminal cells release calcitonin gene related protein (CGRP), a vasodilator neuropeptide which further increases the dilation of the meningeal blood vessels, and further feeds into the trigeminal nerve activation. The local intracranial increased activation of the trigeminal nerve spreads through the trigeminal ganglion into the Trigeminal Nucleus Caudalis (TNC) in the brainstem in a process known as peripheral sensitization. The activation of the TNC leads in turn to a central activation process, through its thalamic and cortical projections, which are illustrated in FIG. 1.

Although the pain associated with migraine involves input from meningeal arteries, activation of the TNC may result in referred pain anywhere along the trigeminal network, including the temporal arteries and temporal muscles. The trigeminocervical network involved in the pathophysiology of migraine contains the three main branches of the trigeminal nerve: the ophthalmic branch (V1), the maxillary branch (V2), and the mandibular branch (V3), as illustrated in FIG. 2; as well as the sensory nerves for the posterior head and neck (C2, C3, C4, C5) that feed into the TNC. A detailed anatomical map of the relevant pathways can be found in pages 316, 317, 600, 601 and 736 of Agur, A. M. R. and Dalley II, A. F. (2005) Atlas of Anatomy 11^(th) Ed., Lippincottt Williams & Wilkins, Philadelphia, which is hereby incorporated by reference.

The activation of the TNC in the brainstem can further spread to the occipital nerve by virtue of its anatomical connection to the TNC, leading to pain sensation in the occipital area.

The activation of the TNC can also spread to the parasympathetic system, by activation of a nearby nucleus in the brainstem, the Superior Salivatory Nucleus (SSN), which is connected to the nucleus caudalis through a network of interneurons, as shown in FIG. 3.

Neurons from the SSN synapse with the Sphenopalatine ganglion, which provides vasomotor innervation to blood vessels and secretomotor innervation to the lacrimal glands, nasal and sinus mucosa. When the parasympathetic system is activated, the upper respiratory tract symptoms associated with migraine occur including, potentially, nasal symptoms (rhinorrhea, and post nasal drip), ocular symptoms (conjunctival injection, and tearing) and sinus congestion (pain or pressure around the sinuses). Other parasympathetic projections further aggravate the cascade of events, like the Sphenopalatine ganglion afferents that innervate the meningeal blood vessels. Activation of the parasympathetic system during a migraine attack is also accompanied by a significant increase in the levels of Vasoactive Intestinal Polypeptide (VIP), a parasympathetic neurotransmitter which causes vasodilation and can be measured in high concentrations during a migraine in the jugular venous drainage.

The increased activity of the trigeminal, occipital and parasympathetic systems just described is common to the so-called Trigeminal Autonomic Cephalgias (TAC), which include Cluster headache, Paroxysmal Hemicrania, SUNCT Syndrome, and Hemicrania Continua.

Cluster headaches are a primary headache disorder involving attacks of less than 3 hours of duration with severe unilateral peri-orbital and temporal pain. These headaches can be associated with lacrimation, nasal congestion, rhinorrhea, conjunctival injection and a Homer's syndrome. The attacks occur in distinct clusters. Cluster headaches typically involve a series of disabling attacks on a daily basis lasting for months at a time. This pattern recurs annually or biannually.

Paroxysmal hemicrania is a primary headache disorder involving frequent attacks of unilateral, peri-orbital and temporal pain typically lasting less than 30 minutes. The pain can be associated with conjunctival injection, lacrimation, nasal congestion, rhinorrhea, ptosis and eyelid edema.

SUNCT Syndrome is a primary headache disorder characterized by multiple attacks of unilateral, peri-orbital and temporal pain typically lasting less than 2 minutes. The pain is associated with conjunctival injection, lacrimation, nasal congestion, rhinorrhea, and eyelid edema. This headache may be associated with trigeminal neuralgia.

Hemicrania Continua is a primary headache disorder characterized by a strictly unilateral headache responsive to Indomethacin. The pain is associated with conjunctival injection, lacrimation, nasal congestion, rhinorrhea, ptosis, and eyelid edema.

The trigeminal nerve is involved in the pain sensations for all of these headache types, as well as headaches triggered by other pathologies. For example, Temporal Arteritis involves inflammation of the temporal artery with painful palpable nodules along the artery. In addition to headache in the temporal area, Temporal Arteritis causes vision loss and jaw pain.

Headaches can also be associated with ischemic stroke. In a stroke, a lack of blood supply to brain tissue causes a sudden localized neurological deficit. In a large number of affected patients, occlusion of the arteries is due to the presence of atherosclerotic plaques in the arteries supplying the brain, for example, the carotid artery and the vertebral basilar artery. The atherosclerotic plaques are often associated with inflammation which further contributes to occlusion of the blood vessel.

Nociceptive fibers stimulated by inflammatory mediators in infectious or allergic rhinitis can also activate the trigeminal brainstem nucleus and precipitate migraine.

TAC and Migraine are difficult to treat. Numerous medications have been used to prevent Cluster and Migraine headaches from occurring, which include, amongst others: Propranolol, Timolol, Divalproex Sodium, Topiramate, Verapamil, Indomethacin and Amitriptyline. These medicines have numerous side effects and patients are poorly compliant with them. In the case of TAC, Indomethacin, in particular, is difficult for patients to tolerate due to gastro-intestinal upset.

All of the headache disorders described above produce disability and better treatment modalities are needed.

Recently, Botulinum toxin has been shown to be effective to treat migraine headaches when injected in the face, cranium and neck (Binder, U.S. Pat. No. 5,714,468). Botulinum toxin is a potent polypeptide neurotoxin produced by the gram positive bacterium Clostridium botulinum which causes a paralytic illness in humans termed Botulism. Botulinum toxin has a light and a heavy chain. The heavy chain attaches to a cell surface receptor and the complex is then endocytosed. After endocytosis, the light chain translocates from the endosome into the cytoplasm, where it cleaves a segment of the SNARE protein complex responsible for vesicle fusion in the presynaptic nerve terminal. As a result, the release of neurotransmitters from these vesicles is effectively blocked for 3-6 months.

There are 7 immunologically distinct toxins: A, B, C1, D, E, F and G (Simpson, et al., Pharmacol. Rev., 33:155-188, 1981). These toxins bind to presynaptic membranes of target nerves and appear to work in a similar fashion (Brin, et al., “Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology”, Neurology, 40:1332-1336, 1990). Botulinum toxin shows a high affinity for cholinergic neurons. Botulinum toxin A produces a reversible, flaccid paralysis of mammalian skeletal muscle, presumably by blocking the exocytosis of acetylcholine at peripheral, presynaptic cholinergic receptors (Rabasseda, et al., Toxicon, 26:329-326, 1988). However, flaccid muscular paralysis is not necessary to achieve the reduction or prevention of migraine symptomatology. In fact, headache pain reduction may be observed at dosages of presynaptic neurotoxin which are lower or higher than dosages required to produce flaccid paralysis of skeletal muscle and without introduction of the neurotoxin into muscle tissue (Binder, U.S. Pat. No. 5,714,468).

Although the molecular basis for the sensation of migraine pain is not clear (Goadsby, et al., N. Eng. J. Med., 346:257-270, 2004), Botulinum toxin might exert its analgesic effect by blocking the release of nociceptive and inflammatory agents that are released during migraine, and not by blocking the release of acetylcholine. Because Botulinum toxin does not act on acetylcholine directly, but on the SNARE protein complex that mediates vesicle fusion, the release of other molecules which is also mediated by the SNARE protein complex is also affected by the toxin (Aoki, Current Medicinal Chemistry, 11:3085-3092, 2004). In fact, studies have shown that Botulinum toxin can also block the release of substance P, which is associated with neurogenic inflammation and pain generation (Aoki, Current Medicinal Chemistry, 11:3085-3092, 2004), glutamate, also associated with nociception (Cui, et al., Pain, 107:125-133, 2004), epinephrine, norepinephrine, and calcitonin gene-related peptide (Aoki, Current Medicinal Chemistry, 11:3085-3092, 2004). Botulinum toxin A does not appear to cause degeneration of nervous or muscular tissue and has been approved for use in certain therapies by the U.S. Food and Drug Administration.

In addition to Botulinum toxin A, other presynaptic neurotoxins have also been suggested to be useful for the treatment of migraine, given the functional characteristics they share with Botulinum toxin (Binder, U.S. Pat. No. 5,714,468). One of these presynaptic neurotoxins is Tetanus neurotoxin, which is produced by Clostridium tetani (DasGupta, et al., Biochemie, 71:1193-1200, 1989), and shows significant sequence homology with serotypes A and E of Botulinum toxin. In particular, fragment Ibc of the Tetanus toxin, which is obtained by peptide digestion of the toxin, appears to act peripherally to produce flaccid paralysis (Fedinic, et al., Boll.lst. Sieroter Milan, 64: 35-41, 1985; and, Gawade, et al., Brain Res., 334:139-46, 1985).

Staphylococcal alpha-toxin has also been suggested for therapeutic use. This toxin stimulates the production in the brain of muscle-relaxing factor (MRF), which results in reversible, flaccid paralysis of skeletal muscle (Harshman, et al., Infect. Immun., 62:421-425, 1994). Staphylococcal alpha-toxin may function similarly to Botulinum toxin.

Other toxins which cause reversible, flaccid paralysis are the acylpolyamine toxins, which are anticholinergic, presynaptic neurotoxins produced in the venom of many invertebrates (Herold, et al., Anesthesiology, 77:507-512, 1992). For example, toxins AR636 and AG489 from spiders Argiope aurantia and Agelenopsis aperta lead to motor inhibition at a dosage of 2 micrograms and sensory inhibition at 7 micrograms.

Since the use of presynaptic neurotoxins to treat migraines was initially implemented by administering the toxins in the face, cranium and/or neck (Binder, U.S. Pat. No. 5,714,468), the hypothesis about the physiological changes underlying migraine has been significantly developed. The present invention provides an improvement in the therapeutic and preventive use of Botulinum toxin, among other presynaptic neurotoxins, to treat migraines, TAC and other headaches associated with vascular conditions by using a new method to administer these neurotoxins. The improvement is based on the recent theory that has emerged about the pathophysiological changes triggering these headaches, which involves the trigeminal, occipital and parasympathetic systems and therefore affects the administration sites of the toxins.

SUMMARY OF THE INVENTION

There is a need in the medical field to provide an effective therapeutic and prophylactic treatment for migraines, TAC, and other headaches associated with vascular conditions. The invention provides a method for reducing or preventing symptoms and in particular pain related to migraines, TAC, and other headaches associated with vascular conditions in mammals, particularly humans. Specifically, the invention provides an improvement for current methods to treat and prevent these headaches with presynaptic neurotoxins. More specifically, the present invention relates to administering a therapeutically effective amount of a pharmaceutically safe presynaptic neurotoxin, peripherally, along the extracranial trigeminal nerve endings in the temporal region, the extracranial occipital nerve endings in the occipital region, as well as along the intranasal trigeminal nerve endings and parasympathetic nerve endings in the nasal mucosa of a mammal.

The presynaptic neurotoxins of the invention will be those presynaptic neurotoxins that produce reversible, localized paralysis of musculature when administered to a mammal (although to practice the invention such paralysis is not needed) and do not cause degeneration of muscle or nervous tissue. Botulinum toxin, and in particular, Botulinum toxin A is a preferred presynaptic neurotoxin of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. Diagram of headache pain pathways, illustrating the input and output pathways of the trigeminal nucleus caudalis in the brainstem.

FIG. 2. Diagram of the trigeminal and parasympathetic network involved in headache pain, from and into the brainstem.

FIG. 3. Diagram of the neural innervation of the cranial circulation, illustrating the trigeminal nociceptive input from the internal carotid to the trigeminal nucleus caudalis of the brainstem, and the connection to the parasympathetic system through the superior salivatory nucleus. The parasympathetic system feeds back into the internal and external carotids, which connect with the temporal and occipital arteries.

FIG. 4. Illustrated lateral view of a human head showing the connection between the external carotid and the superficial temporal and occipital arteries. FIG. 4 has been adapted from Agur, A. M. R. and Dalley II, A. F. (2005) Atlas of Anatomy 11^(th) Ed., Lippincottt Williams & Wilkins, Philadelphia. Refer to pages 316, 317, 600, 601 and 736 of the original reference for a detailed view of the anatomy.

DETAILED DESCRIPTION OF THE INVENTION

The anatomical and physiological theory of migraine, TAC, and other headaches associated with vascular conditions, as described in the Background section, suggests that blockade of the release of nociceptive and inflammatory agents triggered by the hyperactivation of the trigeminal, occipital and parasympathetic systems involved in the development of these headaches should provide an effective therapeutic and/or prophylactic treatment. As FIGS. 1 and 2 show, some of the anatomical pathways involved in the development of these headaches are intracranial; therefore, specific blockade of the intracranial pathways involved by non-invasive means is not feasible. However, some of the pathways affected are located extracranially under the surface of the skin or intranasally, and are therefore accessible to treatment. Some examples of these pathways include the temporal arteries and muscles (FIGS. 1 and 4), the nasal glands and mucosa (FIG. 2) and the occipital nerve and artery (FIG. 4). The current invention relates to providing a method for blocking the release of nociceptive and inflammatory agents triggered by the hyperactivation of the trigeminal, occipital and parasympathetic fibers that is increased during migraine, TAC or other headaches associated with vascular conditions.

The therapeutic modality used to treat and/or prevent the conditions described in this patent is the use of presynaptic neurotoxins. “Presynaptic neurotoxin” as used in this disclosure refers to those neurotoxins and their derivatives which are known to produce localized, reversible flaccid paralysis of musculature in mammals which does not result in degeneration of muscle or nervous tissue. However, as stated earlier, flaccid muscular paralysis which the presynaptic neurotoxins of the invention will produce is not necessary to achieve the reduction or prevention of headache symptomatology with the method of the invention.

In a preferred embodiment, the presynaptic neurotoxin of the invention is Botulinum toxin. In a particularly preferred embodiment of the invention, the presynaptic neurotoxin is Botulinum toxin A. Botulinum toxin A is presently supplied and commercially available as “Botox”® by Allergan, Inc. of Irvine, Calif., and as “Dysport”® by Ipsen, of Berkshire, UK. In another embodiment of the invention, the presynaptic neurotoxin is Botulinum toxin B. Botulinum toxin B is commercialized as “Neurobloc”®/“Myobloc”® by Solstice Neuroscience, Inc, of San Francisco, Calif. A pentavalent toxoid of all eight known Botulinum serotypes is also available as an investigational drug from the U.S. Center for Disease Control in Atlanta, Ga. The Botulinum A toxin preparations are most preferred for their known safety and efficacy. Botox® has also been used to treat, among other things, cervical dystonia, brow furrows, blepharospasm, strabismus, and hyperhidrosis.

Tetanus toxins are also commercially available for use as vaccines. Since the Ibc fragment of the Tetanus toxin is likely to act in a similar fashion to Botulinum toxin, as suggested earlier, a further embodiment of the invention will preferably comprise the use of pharmaceutically safe forms of the Ibc fragment of the Tetanus toxin rather than the intact form of the toxin.

Obtaining the presynaptic neurotoxins of the invention, including the Botulinum and Tetanus toxins, in a pharmaceutically safe form and therapeutically effective amount should be known or easily determined by those of ordinary skill in the art. The presynaptic neurotoxins should preferably be in a nontetragenic form that does not trigger a detectable immune response. Pharmaceutical safety will be dose-dependent for most of the presynaptic neurotoxins of the invention, in such a way that fairly low doses of toxin will be “safe” as compared to doses known to produce disease.

The presynaptic neurotoxins of the invention will be preferably administered as a composition in a pharmaceutically suitable carrier. For this purpose, presynaptic neurotoxin compositions will be prepared for administration by combining a toxin of the desired degree of purity with physiologically suitable sterile carriers. These carriers will not produce toxic responses in recipients at the doses and concentrations used. In a preferred embodiment, the preparation of such compositions typically involves mixing the presynaptic neurotoxin with buffers, antioxidants such as ascorbic acid, low molecular weight (less than about 10 residues) polypeptides, proteins, amino acids, carbohydrates including glucose or dextrins, chelating agents such as EDTA, glutathione and other stabilizers and excipients. These compositions can also be lyophilized and will be pharmaceutically acceptable; i.e., appropriately prepared and approved for use in the desired application.

To facilitate administration, the presynaptic neurotoxins will most preferably be formulated in unit dosage form. The presynaptic neurotoxins may be supplied, for example, as a sterile solution or as a lyophilized powder in a vial.

In general, the amount of presynaptic neurotoxins used for treatment will be determined by the age, gender, presenting condition and weight of the patient, in consideration of the potency of the presynaptic neurotoxin. The potency of a toxin is expressed as a multiple of the LD₅₀ value for a reference mammal. One “unit” of toxin is the amount of toxin that kills 50% of a group of mammals that were disease-free prior to inoculation with the toxin. For example, one unit of Botulinum toxin is defined as the LD₅₀ upon intra peritoneal injection into female Swiss Webster mice weighing 18-20 grams each. One nanogram of the commercially available Botulinum toxin A typically contains about 40 mouse units. The potency in humans of the Botulinum toxin A product currently supplied by Allergan, Inc. as “Botox”® is estimated to be about LD₅₀=2,730 units.

Assuming an approximate potency of LD₅₀=2,730 units, the presynaptic neurotoxin can be administered in a dose of up to about 1,000 units; however, dosages of as low as about 2.5 to 5 units will have therapeutic efficacy. Dosages between 2.5 or 5 units and as high as 250 units will be normally used, and in a preferred embodiment, individual dosages will be of about 15-30 units. Typically, the presynaptic neurotoxin will be administered as a composition at a dosage that is proportionally equivalent to a range of between 1 cc-5 cc/100 units, which translate to 100 units/cc-20 units/cc. Adjustment of these dosages depending on the greater or lesser potency of the presynaptic neurotoxins and factors identified above should be easily determined by those of ordinary skill in the art.

In the preferred embodiment, the dosage used will be the lowest one which is still therapeutically effective (i.e., the dosage which results in detection by the patient of a reduction in the occurrence and/or magnitude of headache pain experienced by the patient, even though other symptoms associated with the pain, such as the premonitory aura, may persist). The patient's sensitivity to, and tolerance of, the presynaptic neurotoxin can be determined in the initial treatment, by administering a low dosage at one site. Additional administrations of the same or different dosages can be provided as needed.

The injections will be repeated as necessary. As a general guideline, Botulinum toxin A administered into or near muscle tissue has been observed to produce flaccid paralysis at target site muscles for up to about 3 to 6 months. However, increased efficacy of the treatment using Botulinum toxin A is expected to happen when the toxin is administered according to the method of the invention at about 3 month intervals.

In a preferred embodiment of the invention, commercially available Botox® can be reconstituted with sterile non-preserved saline prior to injection. Each vial of Botox® contains about 100 units of clostridium Botulinum toxin type A purified neurotoxin complex. Dilutions will vary depending upon the commercial preparation.

The technique of administrating presynaptic neurotoxins to modulate the parasympathetic, trigeminal and occipital nerve responses involved in TAC, migraine and other headaches associated with vascular conditions, involves distributing the presynaptic neurotoxins around the nerve endings involved. Because a high concentration of the trigeminal nerve endings are wrapped around the arteries, injections of presynaptic neurotoxins along the trajectory of the temporal extracranial artery is an effective way of administering presynaptic neurotoxins, and in particular Botulinum toxins, for the treatment of migraine, TAC and other headaches. The same rationale applies to the occipital nerve endings along the extracranial occipital artery. This method helps to locate the synaptic terminals of the targeted nerves, which allows for the maximum adherence of presynaptic neurotoxins to the pain generating nerves involved in headache disorders.

In a preferred embodiment of this invention, the presynaptic neurotoxins are administered by way of injection. However, in other embodiments, the presynaptic neurotoxins may be administered topically. In general, the preparation of the presynaptic neurotoxin solution for topical delivery may be the same as that which is injected. However, in other embodiments, the presynaptic neurotoxin may be applied topically via a carrier known to those of skill in the art. The solutions can then be administered by several means, like for example, a pledget of cotton or cotton tipped applicator, a dropper or a spray in the case of a solution, or a spatula in the case of a cream. These topical methods of application may be used wherever trigeminal, occipital or parasympathetic nerve endings can be accessed efficiently by such application. The solution containing the presynaptic neurotoxins can be administered topically to the epidermis through these means and the presynaptic neurotoxins can then be distributed through the epidermis by transdermal carrier systems. As would be obvious to one of skill in the art, topical administration may not be as effective as administration via injection depending on, for example, the patient, the severity of the symptoms and access to the trigeminal, occipital and parasympathetic nerves.

The target administration sites for the current invention are the extracranial and intranasal trigeminal nerve endings and parasympathetic nerve endings of the nasal mucosa, the extracranial temporal trigeminal endings and the extracranial occipital nerve endings. The parasympathetic nerve endings in the nasal mucosa, also situated around the lacrimal glands are illustrated in FIG. 2. The trigeminal nerve endings are situated around the temporal artery (FIG. 4) and temporal muscle, as shown in FIG. 1, and the occipital nerve endings are located around the occipital arteries (FIG. 4) via cervical nerve roots that connect with the trigeminal spinal nucleus. Presynaptic neurotoxins injected in these locations every 3-6 months produce a therapeutic beneficial effect on migraine, TAC and other headaches associated with vascular conditions.

Nasal Administration

To target the intranasal trigeminal nerve endings and parasympathetic nerve endings in the nasal mucosa, the method of administration involves infiltrating the upper respiratory tract (nasal mucosa and turbinates) with a presynaptic neurotoxin diluted with a suitable solution such as saline. There is a coalescence of nerve fibers within the upper region of the nose (intranasally) near the cribiform plate and above the superior turbinate. It is also known anatomically that the inferior turbinate, which is the most responsive organ in the nose, is formed of bone and mucosa composed of vascular lakes that provide the basis for nasal sprays and topical medications administered intranasally which provide for rapid local transmucosal absorption.

In a preferred embodiment, Botulinum toxin Type A (Botox®) is used, and each nostril is infiltrated with 5 to 10 units using a solution of 100 units of Botox® diluted with 4 cc of normal saline. The infiltration in this preferred embodiment is performed by injection using a 30 gauge needle. Intranasal injections are given in each nostril using endoscopic application, or a needle palpation technique. The needle is inserted through the nostril. Lateral and medial mucosal infiltration is performed either through finger palpation and guidance or through direct visualization using a nasal speculum and an external light source or via endoscopic guidance.

In another embodiment, Botox® is used and it is administered in the region of the external nares using 5 to 10 units using a solution of 100 units of Botox® diluted with 4 cc of normal saline. The infiltration in this preferred embodiment is performed by injection using a 30 gauge needle. If necessary, Botox® can be also administered in the distribution of the infraorbital nerve.

In another embodiment of the invention, infiltration of the presynaptic neurotoxins in the upper respiratory tract will be done by topical administration to the intranasal mucosa (either alone or with a carrier substrate) which, because of its anatomical proximity to the end terminals of the trigeminal nerve or the sphenopalatine ganglion that innervate the nose, will have a direct effect on the alleviation of headache pain. In a particular embodiment, the presynaptic neurotoxin solution, with or without a carrier, will be delivered with a cotton pledget or a dropper and spread along the targeted area. In another embodiment of the invention, the presynaptic neurotoxin solution, with or without a carrier, will be delivered in the form of an emollient, cream or solution, and spread over the epidermis of the targeted area. In yet a different embodiment of the invention, the presynaptic neurotoxin solution, with or without a carrier, will be delivered in the form of a spray. Other embodiments may use alternative methods of topical delivery known to those of skill in the art.

Example 1

A 48 yr. old female patient with chronic migraine associated with rhinorrhea and cervical dystonia was treated with the method of the present invention. Her migraines involved the left hemicranium and were associated with left rhinorrhea. Initial Botulinum toxin treatment using migraine and cervical dystonia protocols improved her headaches, but did not completely abort them, while the rhinorrhea persisted. The patient was treated with intranasal injections of Botox® 2.5 units (4 cc dilution) four times on the left side only, using the needle palpation approach. There was no change in the shape of the nose or the cartilage base. The discomfort was minimal and the bleeding was not excessive. Two weeks after the treatment, both the rhinorrhea and the headache were resolved.

Temporal Administration

To target the extracranial trigeminal nerve endings in the temporal region, the extracranial temporal artery is palpated and the skin is marked where the artery's pulsations are felt. The area is then infiltrated with presynaptic neurotoxins diluted in a suitable solution such as normal saline along the course of the artery. In a preferred embodiment, the presynaptic neurotoxin used is Botulinum toxin A, and the total dose given per artery is 20 units using a solution of 100 units of Botox® diluted with 2-4 cc of normal saline. The infiltration in this preferred embodiment is performed by injection with a 30 gauge needle.

In the case of headaches stemming from Temporal Arteritis, presynaptic neurotoxins are infiltrated around the temporal artery using a similar technique to that just described. In a preferred embodiment of the invention, Botulinum toxin will be administered by injection.

In another embodiment of the invention, infiltration of the presynaptic neurotoxins along the temporal artery will be done by topical administration, in a similar way as that described for the intranasal area. In a particular embodiment, the presynaptic neurotoxin solution will contain a transdermal carrier. In a different embodiment, the presynaptic neurotoxin solution will be delivered in the form of a spray along the temporal artery, and care will be taken to shield the non-targeted areas of the scalp.

Occipital Administration

The occipital artery can be treated in a similar fashion. The artery is located using the following landmarks: the midpoint between the nucal ridge (inion) and the mastoid process is found; light palpation is used to feel the occipital artery's pulse. The hair is separated and the skin is marked along the course of the artery. Presynaptic neurotoxins diluted in normal saline or other suitable solution are infiltrated around each artery. In a preferred embodiment, 20 units of Botox® in divided doses are infiltrated around each artery using a solution of 100 units of Botox® diluted with 2-4 cc of normal saline. The infiltration in this preferred embodiment is performed by injection with a 30 gauge needle.

In another embodiment of the invention, infiltration of the presynaptic neurotoxins along the occipital artery will be done by topical administration, in the same way described earlier for the temporal administration.

Depending on the condition of each patient, the presynaptic neurotoxins will be administered to one of the sites just described, or to multiple sites. In one embodiment, there are multiple administration sites. In a particular preferred embodiment, the doses ranging between 25 units and 250 units are equally divided among the different administration sites. One of skill in the art should readily ascertain how to adjust the number of administration sites and dosages based on individual profiles of weight, gender, age, condition severity and symptoms.

Other Administration Sites

In an embodiment of the invention, one can utilize a direct sphenopalatine administration of presynaptic neurotoxins, which in a preferred embodiment will be Botulinum toxins, and in particular, Botulinum toxin A. In one embodiment, this treatment may follow prior treatments in which the presynaptic neurotoxin had been administered at any of the foregoing sites without sufficient results.

In the case of atherosclerotic disease, presynaptic neurotoxins, preferably Botulinum toxins can be injected directly into the plaque via an intra-arterial catheter. Botulinum toxins will be of benefit as these plaques produce inflammation in the blood vessel wall in response to cholesterol deposits. This inflammation further compromises the diameter of the lumen of the blood vessel. Botulinum toxins will focally reduce this inflammation for 3 to 6 months.

For the administration of presynaptic neurotoxins by injection, dilution dependent syringes with gauging for units rather than volume injected are recommended. This will ensure that the volume injected contains the desired amount of units, since the volume injected will depend on how the original concentration of the presynaptic neurotoxin was diluted when reconstituted. For example, in the embodiment in which 100 units of Botulinum toxin A are reconstituted in 4 cc of normal saline, a specific syringe with demarcations at 0.1 cc of 2.5 units, and at 0.2 cc of 5 units will be used. In another embodiment in which 100 units of Botulinum toxin A are reconstituted in 1 cc of normal saline, the syringe with demarcations at 0.1 cc of 10 units; and at 0.2 cc of 20 units will be used. These delivery tools allow for accurate delivery and recording of the dose given.

The invention having been fully described, examples illustrating its practice should not, however, be considered to limit the scope of the invention. 

1. A method for treating pain in a mammal in need thereof, wherein the pain is associated with a headache from the group consisting of: migraine, trigeminal autonomic cephalgia and headache caused by a vascular condition, the method comprising administering to the mammal having pain, a therapeutically effective amount of botulinum toxin in a pharmaceutically safe form at a site along intranasal trigeminal nerve endings or nasal parasympathetic nerve endings or combination thereof, thereby treating pain in the mammal.
 2. The method of claim 1, wherein the botulinum toxin is selected from the group consisting of botulinum toxin types A, B, C₁, D, E, F and G.
 3. The method of claim 1, wherein the botulinum toxin is botulinum toxin type A.
 4. The method of claim 1, wherein the botulinum toxin is administered with an applicator selected from the group consisting of a dropper, a pledget of cotton, cotton tipped applicator, and a spatula.
 5. The method of claim 1, wherein the botulinum toxin is administered topically.
 6. The method of claim 1, wherein the botulinum toxin is administered with a spray.
 7. The method of claim 1, wherein the botulinum toxin is administered by injection.
 8. The method of claim 1, wherein up to about 1,000 units of botulinum toxin is administered.
 9. The method of claim 8, wherein the botulinum toxin is administered at about 3 month intervals.
 10. The method of claim 1, wherein from about 2.5 units up to about 1,000 units of botulinum toxin is administered.
 11. The method of claim 1, wherein the botulinum toxin is administered at about 3 month intervals. 